Percutaneous vertebral stabilization system

ABSTRACT

The present invention relates to a system for percutaneously installing a vertebral stabilization system. A first anchor is positionable within a body of a patient through a first percutaneous opening and a second anchor is positionable within a body of a patient through a second percutaneous opening. A stabilization member is positionable within the body of a patient through the first percutaneous opening to engage and connect the first and second anchors.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application claiming priority to U.S.application Ser. No. 12/835,118 filed on Jul. 13, 2010, which is a U.S.patent application claiming priority to U.S. application Ser. No.11/244,036 filed on Oct. 6, 2005 which claims priority to U.S.Provisional Application Ser. No. 60/675,102 filed on Apr. 27, 2005, allof which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to a vertebral stabilizationsystem, and more particularly, but not exclusively, to a percutaneousvertebral stabilization system.

BACKGROUND OF THE INVENTION

Many types of spinal irregularities can cause pain, limit range ofmotion, or injure the nervous system within the spinal column. Theseirregularities can result from, without limitation, trauma, tumor, discdegeneration, and disease. Often, these irregularities are treated byimmobilizing a portion of the spine. This treatment typically involvesaffixing a plurality of screws and/or hooks to one or more vertebrae andconnecting the screws or hooks to an elongate rod that generally extendsin the direction of the axis of the spine.

Treatment for these spinal irregularities often involves using a systemof pedicle screws and rods to attain stability between spinal segments.Instability in the spine can create stress and strain on neurologicalelements, such as the spinal cord and nerve roots. In order to correctthis, implants of certain stiffness can be implanted to restore thecorrect alignment and portion of the vertebral bodies. In many cases, ananchoring member such as a pedicle screw along with a vertical solidmember can help restore spinal elements to a pain free situation, or atleast may help reduce pain or prevent further injury to the spine.

As the science and technology of spine surgery continues to progress,there is an increasing interest in developing alternative, minimallyinvasive, methods to conventional “open” spine surgery. The goals ofthese less invasive alternatives are to avoid the surgical exposure,dissection, and retraction of muscles and tissues that is necessary with“open” surgery. In general, a minimally invasive spine surgery systemshould be able to perform the same procedure as the traditional opentechnique, but through smaller incisions instead of one longer incision.As a result, some physicians feel that using a minimally invasive spinesurgery system generally causes less soft tissue damage, reduces bloodloss and reduces recovery time. In addition, patients generally preferthe smaller scars that are left using a minimally invasive approach

Historically, spine fusion surgery including pedicle screw fixation withdeep placement of rods has been one area that has presented significantchallenges for minimally invasive approaches. However, advancement intechnologies such as fluoroscopy and improvements in optics havecontributed to the advent of a few minimally invasive spine fusionsurgery techniques.

One example of instruments and techniques for performing surgery usingminimally invasive techniques is found in U.S. Pat. No. 6,530,929 toJustis et al. The '929 patent discloses a brace installation instrumentthat is mounted to anchors secured in an animal subject. Theinstallation instrument includes anchor extensions coupled to theanchors. The instrument is movable with respect to the anchors toposition a brace in a position more proximate the anchors. The brace canbe indexed for insertion at a predetermined orientation with respect tothe installation instrument. The brace is inserted through anindependent incision in the animal subject and swings along an arc thathas a radius of curvature equal to the distance between the anchors andthe end of the anchor extensions. While these techniques are steps inthe right direction, there remains a need for instruments and methodsfor vertebral stabilization using minimally invasive techniques.

SUMMARY OF THE INVENTION

The present invention relates to a percutaneous vertebral stabilizationsystem. In one aspect of the invention, a first anchor is deliverable toa vertebral body of a patient through a first percutaneous opening withan access sleeve connected thereto. The access sleeve has a centralchannel extending therethrough along a longitudinal axis. Astabilization member is positionable through the first percutaneousopening to engage the first anchor. A stabilization member insertiondevice is releasably and rotatably linked to the stabilization memberand the stabilization member insertion device is configured anddimensioned to be received within the central channel such that theinsertion device and the stabilization member are moveable in thelongitudinal direction along the longitudinal axis to position thestabilization member adjacent the first anchor. The stabilization memberis deliverable through the central channel in the access sleeve in afirst orientation substantially parallel to the longitudinal axis of theaccess sleeve. Independent of movement along the longitudinal axis, thestabilization member is rotatably actuatable by the stabilization memberinsertion device to extend in a second orientation angled with respectto the first orientation to position the stabilization member inrelation to the first anchor.

In another aspect of the invention, the system comprises a second anchordeliverable to a vertebral body of a patient through a secondpercutaneous opening with a second access sleeve connected to the secondanchor. In one variation, the stabilization member insertion device isoperable to place the stabilization member in a predetermined positionrelative to the first and second anchors.

In one embodiment, the insertion device extends from a proximal end to adistal end along a longitudinal axis, and the insertion device comprisesa first member and a second member. The first member is linearlytranslatable with respect to the second member along the longitudinalaxis. The stabilization member is linkingly engaged to the first memberand rotatably engaged to the second member such that, when the firstmember is translated with respect to the second member along thelongitudinal axis the stabilization member rotates about the secondmember.

In another embodiment, the first anchor comprises a coupling elementconnected to the access sleeve, and the coupling element comprises aportion for receiving the stabilization member. When the couplingelement is connected to the access sleeve the receiving portion isunobstructed. In another aspect of the invention, each sleeve includes apair of longitudinal openings extending along opposing lateral sides andthe openings providing lateral access to the central channel. In oneembodiment, the insertion device is configured to be received in thecentral channel and at least a portion of the stabilization member isextendable through the longitudinal openings.

In another aspect of the invention, the first and second anchors have apredetermined orientation within the body and the stabilization memberhas a geometry corresponding to the predetermined orientation of thefirst and second anchors. In one embodiment of the invention, the firstand second anchors comprise polyaxial screws.

In another aspect of the invention, the stabilization member comprises arod and in one particular embodiment of the invention the rod may have acurvilinear shape. In one embodiment, the rod has at least oneindentation along its length, wherein the stabilization member insertiondevice is rotatably linked to the stabilization member about theindentation. In another embodiment, the rod has a proximal endconfigured and dimensioned to interact with the stabilization memberinsertion device.

The present invention also relates to a method of percutaneouslyinstalling a vertebral stabilization system. In one exemplaryembodiment, a first percutaneous opening is created in a body of apatient and the method comprises positioning a first anchor to avertebral body within the patient through the first percutaneous openingwith an access sleeve connected thereto. The method further comprises,positioning a stabilization member through the first percutaneousopening to engage the first anchor. The stabilization member isrotatably linked to a stabilization member insertion device, and thestabilization member insertion device is configured and dimensioned tobe received within the sleeve such that the insertion device andstabilization member are moveable in the longitudinal direction toposition the stabilization member adjacent the first anchor. The methodfurther comprises positioning the stabilization member along thelongitudinal axis through the central channel in the access sleeve in afirst orientation substantially parallel to the longitudinal axis of theaccess sleeve; and rotating the stabilization member with respect to theinsertion device independent of movement along the longitudinal axissuch that the stabilization member extends in a second orientationangled with respect to the first orientation to position thestabilization member in relation to the first anchor.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more readily understood with reference to theembodiments thereof illustrated in the attached drawing figures, inwhich:

FIG. 1 is a perspective view of one embodiment of a percutaneousvertebral stabilization system according to the present invention;

FIG. 2 is an expanded view of one embodiment of an anchor according tothe present invention;

FIG. 3 is a perspective view of one embodiment of a sleeve according tothe present invention shown in a first position;

FIG. 4 is an enlarged partial perspective view of the sleeve of FIG. 3shown engaging a portion of the anchor of FIG. 2;

FIG. 5 is a perspective view of the sleeve of FIG. 3 shown in a secondposition;

FIG. 6 is an enlarged partial perspective view of the sleeve of FIG. 3shown without an anchor retained therein;

FIG. 7 is a perspective view of one embodiment of a stabilization memberinsertion device according to the present invention;

FIG. 8 is a perspective view of one embodiment of a stabilization memberaccording to the present invention;

FIG. 9 is an enlarged partial perspective view of the stabilizationmember of FIG. 8;

FIGS. 9A-9C are enlarged side views of alternative indentations of thestabilization member of FIG. 9;

FIG. 10 is an enlarged partial perspective view of the insertion deviceof FIG. 7 shown in a first position;

FIG. 11 is an enlarged partial perspective view of the insertion deviceof FIG. 7 shown in a second position;

FIG. 12 is another enlarged partial perspective view of the insertiondevice of FIG. 7 shown in a first position;

FIG. 13 is a perspective view of one embodiment of a distractor deviceaccording to the present invention;

FIG. 14 is an enlarged partial perspective view of the distractor deviceof FIG. 13 shown in a first position;

FIG. 15 is an enlarged partial perspective view of the distractor deviceof FIG. 13 shown in a second position;

FIG. 16 is another embodiment of a sleeve according to the presentinvention shown engaging a portion of the anchor of FIG. 2; and

FIG. 17 is an enlarged partial perspective view of the sleeve of FIG.16;

FIG. 18 is a perspective view of one embodiment of an alignment deviceaccording to the present invention;

FIG. 19 is a side view of one embodiment of a sleeve attachment memberaccording to the present invention;

FIG. 20 is a side view of another embodiment of a connecting elementaccording to the present invention;

FIG. 21 is an exploded view of another embodiment of a stabilizationmember insertion device according to the present invention;

FIGS. 22-23 are perspective views of another embodiment of astabilization member according to the present invention;

FIG. 24 is a perspective view of the forked assembly of insertion deviceof FIG. 21;

FIGS. 25-26 are perspective and cross-sectional views of the pusherassembly of FIG. 21;

FIG. 27 is a perspective view of the pusher member of FIGS. 25-26;

FIG. 28 is a perspective view of the retainer tube assembly of FIG. 21;

FIGS. 29-30 are side views of a rod reducer assembly according to thepresent invention.

FIG. 31 is a perspective view of the assembly of FIGS. 29-30 shown inoperation in a first position;

FIG. 32 is a perspective view of the assembly of FIGS. 29-30 shown inoperation in a second position;

FIG. 33 is partial cross-sectional view of a reducer shaft of theassembly of FIGS. 29-30;

FIG. 34 is an end view of the shaft of FIG. 33; and

FIG. 35 is a perspective view of an attachment sleeve for use with theassembly of FIGS. 29-30.

Throughout the drawing figures, it should be understood that likenumerals refer to like features and structures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the invention will now be described withreference to the attached drawing figures. The following detaileddescription of the invention is not intended to be illustrative of allembodiments. In describing preferred embodiments of the presentinvention, specific terminology is employed for the sake of clarity.However, the invention is not intended to be limited to the specificterminology so selected. It is to be understood that each specificelement includes all technical equivalents that operate in a similarmanner to accomplish a similar purpose.

Referring to FIG. 1, one embodiment of a system 10 according to theinvention is shown. System 10 generally comprises a first anchor 12, asecond anchor 14, and a connecting member or stabilization member 16that is configured to connect and/or extend between the first and secondanchors 12, 14 for stabilizing at least a portion of a vertebrae of apatient. First anchor 12 is positionable within a body of a patientthrough a first percutaneous opening 18 and a second anchor 14 ispositionable within a body of a patient through a second percutaneousopening 20. In one embodiment, first and second anchors 12, 14 areconfigured to engage first and second vertebra 21, 23. Stabilizationmember 16 is positionable within the body of a patient through firstpercutaneous opening 18 to engage and connect first and second anchors12, 14. Sleeves 22, 24 extend from anchors 12, 14 and facilitateinsertion of anchors 12, 14 and stabilization member 16 and fixation ofstabilization member 16 to anchors 12, 14. Stabilization member 16 maybe installed percutaneously or non-percutaneously into receivingportions or channels 26 of anchors 12, 14. Connecting member orstabilization member 16 generally comprises an elongate rod or shaft.Stabilization member 16 may have an arcuate or curvilinear shape. Inalternative embodiments, however, stabilization member 16 can includeany configuration known for a rod, implant, or fastener, and can bestraight or have any curvature along its length including a compoundcurvature. As shown in FIG. 1, a stabilization member insertion device30 may be inserted into sleeve 22 to facilitate insertion ofstabilization member 16 into anchors 12, 14.

In one embodiment, stabilization member insertion device 30 isreleasably and rotatably linked to the stabilization member 16 and thestabilization member insertion device 30 is configured and dimensionedto be received within the sleeves 22, 24 such that the insertion device30 and stabilization member 16 are moveable in the longitudinaldirection within the sleeve to position stabilization member 16 adjacentthe anchors 12, 14. As will be discussed in more detail below,stabilization member 16 is deliverable through the sleeve in a firstorientation substantially parallel to the axis of the sleeve and isrotatable to a second orientation at an angle with respect to the firstorientation. Furthermore, the stabilization member 16 is rotatablyactuatable by insertion device 30 independent of movement along the axisof the sleeve, i.e. the stabilization member 16 may be rotated byinsertion device 30 anywhere along the length of the sleeves 22, 24.Such a feature may be particularly advantageous, for example, to adjustthe pathway or route that the stabilization member 16 travels throughthe body tissue during installation. In addition, due to the independentaspect of the rotation of the stabilization member, rotation may beactuated or independently controlled without moving the insertion devicewith respect to the sleeves 22, 24. In this regard, rotation ofstabilization member 16 may be rotated without downward exertion offorce upon the sleeve and/or anchor.

Each of the first and second anchors 12, 14 generally comprises a bonefastener such as a bone screw 32 with a head 34 and a shaft or shank 36having bone engaging threads. As shown in FIG. 2, screw 32 is cannulatedwith a central passage or lumen 38 extending along a central axis 39,however, non-cannulated screws may also be used. Head 34 includes a toolengagement surface or opening 40 configured to receive a driving tool toprovide torque and drive the screw into bone. In one embodiment, screw32 is a polyaxial screw assembly that has a coupling element 42pivotably coupled to head 34 of screw 32. In this regard, screw 32 iscapable of rotating within coupling element 42 to assume a plurality ofangles. One example of a polyaxial screw that may be used with thepresent invention is described in co-pending U.S. patent applicationSer. No. 10/826,285, the entire contents of which are incorporated byreference.

Referring to the embodiment of FIG. 2, coupling element 42 is configuredand adapted to receive the stabilization member 16. In general, couplingelement 42 includes a U-shaped body 44 defining a channel 26 in whichstabilization member 16 may be locked or fixed in place by, for example,a locking cap. In alternate embodiments, alternative means of rigidlycoupling stabilization member 16 to an anchor may be used by thoseskilled in the art, including alternative configurations of couplingelements and locking devices or methods. In one embodiment, couplingelement 42 includes features to couple with sleeves 22, 24.

In the illustrated embodiment, sleeves 22, 24 may extend from each ofthe anchors 12, 14 and provide a portal or passageway through the bodyof a patient to access anchors 12, 14. Referring to FIGS. 3-6, oneembodiment of a sleeve 50 according to the invention is shown comprisingan inner sleeve member 52 and an outer sleeve member 54 extending from aproximal end 56 to a distal end 58 along an axis 60. Inner sleeve member52 and outer sleeve member 54 have a central channel 62 extendingaxially through sleeve 50 and the sleeve members 52, 54 are axiallyslidable with respect to each other. Outer sleeve member 54 generallycomprises an extended tube with a generally cylindrical top portion 64and a pair of generally rigid arms 66, 68 extending axially from topportion 64 in a distal direction. Inner sleeve member 52 generallycomprises an extended tube with a generally cylindrical top portion 70and a pair of semi-cylindrical flexible arms 72, 74 extending axiallyfrom top portion 70 in a distal direction. Slots or openings 76 extendalong the lateral sides of sleeve 50 to provide access to centralchannel 62 of sleeve 50. Openings 76 extend axially between the arms ofthe inner and outer sleeve members from the top portion to the distalend of the sleeve members. According to one embodiment, a slot 78 may beprovided adjacent the proximal end of top portion 64 of inner sleevemember 52 to engage a pin 80 extending radially inward from the topportion 70 of outer sleeve member 54 to orient the sleeve members 52, 54together and align the openings 76 between the inner and outer sleevemembers. Sleeve 50 may be made of any material suitable for surgicalinstruments. In one preferred embodiment, sleeve 50 may be made of ametal material.

In operation, arms 72, 74 of inner sleeve member 52 may be compressedradially inward or expanded radially outward depending on the particularapplication. Inner sleeve member 52 also includes a retainer portion 82at its distal end to attach an anchor to the distal end of sleeve 50. Asbest seen in FIG. 4, arms 72, 74 may include finger members 84 extendinglaterally inward from the distal end to provide additional retentioncapability.

In FIGS. 3-5, sleeve 50 is shown with coupling element 42 of bone screw32 is received within retainer portion 82 at a distal end 58 of innersleeve member 52 of sleeve 50. In one variation, bone screw 32 may beinserted into inner sleeve member 52 from the bottom or distal end 58when the inner sleeve member 52 is extended axially outside of the outersleeve member (the position shown in FIG. 3). In this regard, retainerportion 82 may snappably or resiliently receive the coupling element 42of screw 32. The inner wall 85 of retainer portion 82 is shaped toconform to the outer perimeter of coupling element 42 such that whenarms 72, 74 of inner sleeve member 52 are compressed radially inward,the coupling element 42 of screw 32 is rotationally and axially fixedwith respect to sleeve 50 or radially contained within sleeve 50. Asshown in FIG. 6, in one embodiment, the inner wall 85 of retainerportion 82 includes a bottom ridge wall 86 and an upper ridge wall 88.Bottom ridge wall 86 is configured and adapted to engage the undersideof coupling element 42 of screw 32 and upper ridge wall 88 is configuredand adapted to engage the top of coupling element 42 to axially fixscrew 32 with respect to sleeve 50. When outer sleeve member 54 is sliddown over inner sleeve member 52, inner sleeve member 52 compressesagainst or radially contains coupling element 42 to hold it firmlyagainst the inner wall 85 of retainer portion 82. Furthermore, fingermembers 84 provide additional retention capability along the lateralsides of coupling element 42. In this regard, anchors 12, 14 may bemounted to sleeve 50 and held in a fixed position relative to sleeve 50and axis 60 of sleeve 50 is aligned with axis 39 of bone screw 32 suchthat when a guidewire, or a tool is inserted into screw 32, screw 32 andsleeve 50 are maintained in this aligned position. Furthermore, when thecoupling element is attached to sleeve 50, the channel 26 or portion forreceiving the stabilization member is unobstructed such that thestabilization member or rod may be unimpeded by, for example, a shelf,guide, ramp, or any other protrusion extending inward from the sleeveinterior, during insertion into channel 26. In addition, installation ofthe stabilization member into channel 26 is simplified without having toremove such an obstruction prior to inserting the stabilization memberinto channel 26.

Referring now to FIG. 18, one embodiment of an alignment tool 200 isshown that may be used with system 10 of FIG. 1. Alignment tool 200generally comprises a connecting element 202 extending between sleeveattachment members 204. Sleeve attachment members 204 are configured anddimensioned to attach to the proximal end 205 of sleeves 22, 24. In onevariation, connecting element 202 may have a cylindrical cross-section.In other embodiments, connecting element 202 may have a polygonal ormultisided cross-section. In the embodiment of FIG. 18, the connectingelement 202 is shown extending along a lateral side of sleeves 22, 24,however, in alternate embodiments, connecting element 202 may be placedor located on either side, or both sides, of the sleeves 22, 24.Connecting element 202 is configured to connect to sleeve attachmentmembers 204 to constrain or align sleeve 22, 24 in a common plane. Forexample, as shown in FIG. 18, the longitudinal axis 206 of sleeve 22 iscoplanar with axis 208 of sleeve 24 when alignment tool 200 is attachedto system 10. By extension, the channels of anchors 12, 14 are alignedsuch that when stabilization member 16 is inserted, it may reliablyalign and extend from first anchor 12 to second anchor 14. In oneembodiment, shown in FIG. 18, the connecting element 202 comprises alongitudinal rod 210. Referring to FIG. 19, another embodiment ofconnecting element 202 is shown and element 202 comprises a bar or plate212 having a slot 213. In alternate embodiments, connecting element 202may have any alternate shape known to those skilled in the art such thatthe axes 206, 208 of sleeves 22, 24 to which it is connected arecoplanar when alignment tool 200 is attached.

Referring to FIG. 20, in one embodiment sleeve attachment member 204 maycomprises a C-shaped clip 214. Clip 214 generally comprises arms 215defining an open end 216 configured and dimensioned to engage and attachto the proximal ends 205 of sleeves 22, 24. In this regard, clip 214 maycomprises parallel flat surfaces 218 on the inner surface thereof toengage, register, and/or align with openings 220 of sleeves 22, 24 tomaintain the sleeves 22, 24 in a fixed position with respect to clip214. In one variation, clip 214 may include protrusions 222 extendingradially inward from the inner surface such that clip 214 may snappedlyengage sleeves 22, 24. Threaded mounting holes 224, extend through thearms 215 of clip 214 to mount the connecting element 202 thereto. Forexample, in the slotted bar embodiment shown in FIG. 19, a set screw 226may be used to attach the slotted plate 212 to clip 214. Also, oncesleeves 22, 24 are aligned with the alignment tool 200, there is stillflexibility to move sleeves 22, 24 with respect to each other and as aunit. Once attached, slotted plate 212 may be adjusted along the slot213 to move the proximal ends 205 of sleeves 22, 24 closer together orfurther apart, as desired. Similarly, in the rod shaped connectingelement shown in FIG. 18, the proximal ends 205 of sleeves 22, 24 may bemoved along the rod 210. Furthermore, once alignment tool 200 isattached to system 10 the sleeves 22, 24 may be moved together as a unitangularly about the distal ends 207, while maintaining coplanarrelationship of axes 206, 208 and alignment of channels 26 of theanchors 12, 14.

Referring now to FIGS. 7-12, one embodiment of a stabilization member 16and insertion device 30 is shown. As shown in FIGS. 8 and 9,stabilization member 16 generally comprises an elongate rod 100extending from a proximal end 102 to a distal end 104 along an axis 106.In one embodiment, rod 100 is curved or arcuate along its length.However, in alternate embodiments, rod 100 may have any alternate shape.According to one aspect of the embodiment, rod 100 includes a generallytapered or conical shaped nose or tip 108 at its distal end 104 tofacilitate insertion and installation of rod 100 into the body of apatient. In alternate embodiments, tip 108 may have varied shapes andsizes.

A linkage connector 110 is provide at the proximal end 102 of rod 100and comprises a pair of generally flat arm members 112, 114 extendingproximally from proximal end 102 of rod 100. Holes 116,118 extendthrough each arm member 112, 114, respectively and are coaxiallypositioned along a linkage axis 120. Holes 116, 118 are configured anddimensioned to linkingly engage a driving link arm 132 of insertiondevice 30. In one embodiment, rod 100 is removably linked to arm 132such that rod 100 may be detached from arm 132 as desired by an operatorof insertion device 30. In another embodiment, ball detents 134 protrudeoutward from arm 132 to engage holes 116, 118. In this regard, slots 122may be provided adjacent holes 116, 118 to facilitate insertion andremoval of ball detents from holes 116, 118.

Referring again to FIG. 8, in one embodiment, rod 100 may include a pairof diametrically opposed indentations 124 spaced from proximal end 102of rod 100. Indentations 124 are coaxially aligned on a pivot axis 126that extends generally perpendicular to a central axial plane of rod 100and pivot axis 126 generally defines an axis about which rod 100 maypivot. Indentations 124 are configured and dimensioned to releasablyrotatably engage pivot arms 136, 137 of insertion device 30 such thatrod 100 may pivot with respect to pivot arms 136, 137. In a preferredembodiment, indentations 124 comprise semispherical concave shapes thatcooperatively engage semispherical protrusions 138 extending from pivotarms 136, 137. In alternative embodiments, shown in FIGS. 9A-9C,indentations 124 may comprise alternative shapes when viewed along axis126 such as a pair of laterally spaced semi-circular indentations 125shown in FIG. 9A, a pair of laterally spaced rectangular indentations127 shown in FIG. 9B, or a pair of laterally spaced triangularindentions 129 shown in FIG. 9C. To attach rod 100 to pivot arms 136,137, the pivot arms may be resiliently expanded slightly to allowprotrusions 138 engage or snap into indentations 124. In operation, onceprotrusions 138 cooperatively engage indentations 124, rod 100 mayrotate or pivot about pivot axis 126.

Referring to FIGS. 7 and 10-12, stabilization member insertion device 30generally comprises an outer tube 140 and an inner shaft 142concentrically disposed within outer tube 140. Inner shaft 142 ismoveable with respect to outer tube 140 along a longitudinal axis 144.Knob 143 is internally threaded to mate with external threads of innershaft 142 such that rotation of knob 143 causes linear translation ofinner shaft 142 with respect to outer tube 140 along axis 144. Endmember 146 is rotatably linked to the distal end of inner shaft 142 andis rotatably linked to the proximal end 148 of a driving link arm 136about an axis 150. The distal end of driving link arm 136 is rotatablylinked to the proximal end 102 of rod 100. A pair of pivot arms 136, 137extend distally from the outer tube 140 and releasably link to rod 100at pivot axis 126. In operation, when shaft 142 is moved downward or inthe distal direction along axis 144 with respect to outer tube 140,driving link arm 136 pushes or drives the proximal end 102 of rod 100downward or in the distal direction and causes rod 100 to rotate orpivot about pivot axis 126. Thus, rod 100 is moveable from a generallyupright orientation or position or a position wherein axis 144 isaligned with or parallel to axis 106 (FIG. 10) to a more horizontalorientation or position or a position wherein axis 144 is perpendicularor angled with respect to axis 106 (FIG. 11). As described above, in oneembodiment stabilization member 16 is rotatably actuatable by insertiondevice 30 independent of movement along the axis of the sleeve, i.e. thestabilization member 16 may be rotated by insertion device 30 anywherealong the length of the sleeves 22, 24.

Referring now to FIGS. 21-28, another embodiment of a stabilizationmember 228 and insertion device 230 is shown. As shown in FIGS. 22 and23, stabilization member 228 generally comprises an elongate rod 232extending from a proximal end 234 to a distal end 236 along an axis 238.Rod 232 is similar to rod 100 in many respects, however, proximal end234 differs from proximal end 102 of rod 100. Proximal end 234 of rod232 comprises a generally concave or rounded ramped tip surface 240angled with respect to longitudinal axis 238 configured and dimensionedto interface or engage with an actuating or pushing member 242 ofinsertion device 230. Rod 232, like rod 100 described above, includesdiametrically opposed indentions 244 that function similar toindentations 124 described above such that rod 232 may rotate about apivot axis 246 extending between indentations 244 when rod 232 isconnected to insertion device 230.

Referring again to FIG. 21, stabilization member insertion device 230 issimilar to insertion device 30 except rod 232 is not positively linkedat its proximal end 234 to a driving link arm as described above withrespect to proximal end 102 of rod 100. Insertion device 230 generallycomprises a forked assembly 250, a pusher assembly 252, and a retainertube assembly 254. As best seen in FIG. 24, forked assembly 250generally comprises an elongate shaft 256 at a proximal end 258 and apair of prongs or fork tines 260 at a distal end 262. As best seen inFIGS. 25-27, pusher assembly 252 generally comprises a pusher member 242linkingly connected to a hollow turning shaft 264 by a slider 266.Slider 266 is freely rotatably connected to turning shaft 264 at itsdistal end such that rotation of shaft 264 causes translation of slider266 in the distal direction along axis 245. Device 230 is similar todevice 30 except driving link arm 136 of device 30 is replaced with apusher member 242 that includes a distal end 268 configured anddimensioned to pushingly and/or slidingly engage proximal end 234 of rod232. The pair of forked tines 260 extends distally from forked assembly250 and are releasably linked to rod 232 by ball engaging detents 270 atpivot axis 246. In this regard, tines 260 are resiliently and outwardlyexpandable such that rod 232 may be inserted between detents 270positioned adjacent the distal end of fork assembly 250.

Forked assembly 250 is dimensioned to be cooperatively received withinhollow turning shaft 264 such that tines 260 extend on either side ofpusher member 242. A threaded section 257 of forked assembly 250 isconfigured to interface with internal threads of knob 265. Retainer tubeassembly 254 generally comprises a cylindrical tube 272 with alongitudinal slot 274 configured to engage a pin 276 of sleeves 22, 24,to ensure proper angular alignment with respect to sleeves 22, 24. Ahandle 278 may be provided to facilitate insertion of tube 272 intosleeves 22, 24, and to provide a longitudinal or axial stop to ensurethat tube 272 extends a sufficient length into sleeves 22, 24, such thatrod 232 may be positioned sufficiently proximate to anchors 12, 14attached to the distal ends of sleeves 22, 24.

In operation, when knob 265 is rotated, turning shaft 264 is rotatedwith respect to forked assembly 250 and slider 266 is moved downward orin the distal direction along axis 245 and pusher member 242 pushes ordrives the proximal end 234 of rod 232 downward or in the distaldirection and causes rod 232 to rotate or pivot about pivot axis 246.Thus, rod 232 is moveable from a generally upright orientation orposition or a position wherein axis 245 is aligned with axis 247 to amore horizontal orientation or position or a position wherein axis 245is perpendicular or angled with respect to axis 247. As described above,in one embodiment stabilization member 16 is rotatably actuatable byinsertion device 230 independent of movement along the axis of thesleeve, i.e. the stabilization member 16 may be rotated by insertiondevice 230 anywhere along the length of the sleeves 22, 24.

In general, insertion device 30 and 230 are similar in that each devicegenerally comprises a first member and a second member, wherein thefirst member is linearly translatable with respect to the second memberalong the longitudinal axis of the device and the stabilization memberis linkingly engaged to the first member and rotatably engaged to thesecond member. When the first member is translated with respect to thesecond member along the longitudinal axis, the stabilization memberrotates about the second member.

Referring now to FIGS. 13-15, one embodiment of a distractor tool 150according to the invention is shown. Distractor tool 150 operatessimilarly to insertion device 30 described above except that it has agenerally straight distractor bar 152 linkedly attached to its distalend 154. The proximal end 156 of distractor bar 152 is rotatably linkedto the distal end of a push rod 158 that rotates distractor bar 152about axis 160. In operation, when push rod 158 is moved downward or inthe distal direction along axis 162 push rod 158 pushes or drives theproximal end 156 of distractor bar 152 downward or in the distaldirection and causes distractor bar sleeve 50 or 170152 to rotate aboutaxis 160. Thus, distractor bar 152 is moveable from a generally uprightposition or a position wherein axis 162 is aligned with axis 164 (FIG.14) to a more horizontal position or a position wherein axis 162 isperpendicular to axis 164 (FIG. 15). Distractor tool 150 is configuredand dimensioned to be received within sleeve 50 or 170 and may beutilized to distract or move tissue positioned between first and secondanchors 12, 14. In this regard, distractor tool 150 may be used by asurgeon to clear a pathway in the body of a patient so thatstabilization member 16 may be subsequently more easily inserted.According to one aspect of the present invention, distractor bar 152 hasan angled tip and a generally straight blade-like shape to facilitatetissue separation.

Referring now to FIGS. 29-35, one embodiment of a rod reducer instrument300 is shown that is configured and dimensioned to be utilized with thepercutaneous systems described herein. Rod reducer instrument 300generally comprises a rotation shaft 302, a reducer shaft 304, and anattachment sleeve 306 configured to engage and attach to a proximal endof sleeves 22, 24. Rotation shaft 302 comprises a through-hole 310adjacent a distal end of shaft 302 and is configured to receive a pin312 therethrough to axially connect rotation shaft 302 to reducer shaft304. Pin 312 is configured to engage a radial slot 314 of shaft 304 suchthat shaft 304 may rotate freely while remaining axially fixed to shaft302. Rotation shaft 302 comprises an externally threaded section 308along a portion of the shaft configured to threadedly engage or matewith corresponding internal threads along the interior of attachmentsleeve 306. Referring to FIG. 35, attachment sleeve 306 generallycomprises a distal end having arms 315 adjacent the distal end defininga lateral opening 316 configured and dimensioned to engage and attach tothe proximal end 205 of sleeves 22, 24. In this regard, arms 315 maycomprise parallel flat surfaces 318 on the inner surface thereof toengage, register, and/or align with openings 220 of sleeves 22, 24 tomaintain the attachment sleeve 306 in a fixed position with respect to asleeve 22, 24 attached thereto.

As best seen in FIG. 33, reducer shaft 304 is a cannulated shaftincluding a central lumen 320 extending therethrough. Radial indentationor slot 314 is provided adjacent the proximal end to axially connectwith rotation shaft 302. The proximal end of shaft 304 includes arotation tool engaging feature to facilitate rotation of shaft 304 andthe distal end of shaft 304 is configured to hold a cap. Referring toFIG. 34, in one embodiment, the distal end comprises cap engaging orholding protrusions 322 extending inward to engage a cap. Furthermore, apair of slits 324 may be provided to allow slight movement of the distalend of shaft 304 to releaseably engage the fastener cap. A key slot 326may be provided to facilitate entry and alignment with sleeves 22, 24and by extension anchors 12, 14 attached at the distal end thereof. Thecap held in the distal end has a channel or trough to engage the rod topush the rod downward toward the fastener. Referring to FIGS. 31 and 32,in operation, as shaft 302 is threadedly rotated with respect toattachment sleeve 306, reducer shaft 304 is translated in the axialdirection and yet does not rotate, providing a force in the axialdirection that may be used, for example, to force a spinal rod from afirst position spaced from a fastener (FIG. 31) to a second positionproximate to a fastener at the distal end of sleeves 22, 24 (FIG. 32).Once in place, the reducer shaft 304 can be rotated to click and/orinstall the cap into each fastener. In one embodiment a hex driver maybe inserted through cannulated rotation shaft 302 to engage the proximalend of reducer shaft 304 to rotate reducer shaft 304 and to rotate thecap with respect to the fastener to install the cap into the proximalend of the fastener. Once the cap is installed another driving tool maybe inserted through rotation shaft 302 and lumen 320 of shaft 304 torotationally engage a set screw and the set screw can then be tightenedto secure the rod in place. The rod reducer instrument 300 can then beremoved from sleeves 22, 24, leaving the stabilization member 16installed in the anchors 12, 14.

Referring to FIGS. 16-17, an alternative embodiment of a sleeve 170according to the present invention is shown. Sleeve 170 generallycomprises a unitary sleeve body 172 extending from a proximal end 174 toa distal end 176 along a longitudinal axis 178. A central channel 180extends axially through sleeve body 172 and a pair of longitudinal slotsor openings 182 extend through the sleeve sidewall 184 alongdiametrically opposite lateral sides of sleeve body 172 and provideaccess to central channel 180. Central channel 180 may have any desiredcross-sectional shape when viewed in an end view. In one embodiment,central channel 180 is sized and dimensioned to permit a screw cap (notshown) to be inserted therein. In a preferred embodiment, channel 180 issized and dimensioned to receive a screw therein such that the screw maybe inserted from the top or proximal end 174 of sleeve 170. Sleeve 170may also include one or more resilient tabs 186 integral with thesidewall 184. Tabs 186 include a radially inward protruding ramp portion188 and a lip portion 190. When a screw, such as screw 32 depicted inFIG. 2, is inserted from the proximal end 174 of sleeve 170 and slidaxially toward the distal end 176, the coupling element 42 of screw 32engages ramp portion 188 to push out or radially expand tabs 186 andallow screw 32 to move distally beyond lip portion 190. Once screw 32 isin a position distally beyond lip portion 190, tabs 186 resilientlyspring back radially inward such that lip portion 190 prevents couplingelement 42 from moving upward or in the proximal direction.

Sleeve 170 has a retention portion 194 at its distal end that is similarto the embodiment of FIGS. 3-6 described above, except in thisembodiment screw 32 is contemplated to be top loaded or inserted intothe proximal end 174 of sleeve 170. Another feature of the presentembodiment is sleeve 170 includes a breakable or separatable connectionat its distal end. In this regard, sleeve 170 may include a break lineor cut 196 to facilitate controlled breakage of sleeve 170 at its distalend 176. Sleeve 170 may be made of any material suitable for surgicalinstruments. In one preferred embodiment, sleeve 170 may be made from aplastic material.

Surgical techniques or methods using the above described system anddevice will now be described. According to one embodiment of the presentinvention, anchors 12, 14 may be implanted into the vertebraepercutaneously. In one preferred embodiment, each of the anchors 12, 14is attached to, mounted on, or retained in sleeve 50 or 170, and thesleeve 50 or 170 and attached anchor are inserted through an openincision, a tube or cannula, or directly through the skin and tissue ofthe patient to implant anchors 12, 14 in bone, such as the pedicles of avertebrae, as shown in FIG. 1. In alternate embodiments, anchors 12, 14can be implanted into bone without a sleeve 50 or 170 attached thereto,and sleeve 50 or 170 may be mounted on an anchor after it is implanted.

The methods of the present invention can employ any imaging system knownto those skilled in the art to determine and locate optimum placementand orientation of the anchors in the vertebrae and/or to identifylocations for percutaneous skin puncture for entry of the anchors. Othermethods known by skilled artisans for locating and placing anchors 12,14 into the vertebrae may be also used, including, but not limited to, aCT scan or x-ray, any known viewing instrument or apparatus, endoscopic,and microscopic monitoring.

In one embodiment, after location of the pedicle entrance point, thepercutaneous instrumentation of the pedicle may begin with the insertionof a cannulated needle through the skin of a patient to the intersectionof the facet and transverse process of a vertebral body to which ananchor is to be implanted. A Kirschner wire or guidewire may be insertedthrough the needle cannula and into the pedicle. Successive dilationcannulas may be subsequently inserted over the guidewire to dilate thefascia and muscle until a working cannula is large enough to accommodateanchor 12 or 14. All but the largest cannula may be removed from theworking cannula to expose a passageway though the skin to the pedicle orinsertion site. In one embodiment, a hole in the pedicle may be preparedby placing a cannulated drill and/or tap over the guidewire and throughthe working cannula to prepare the pedicle for screw insertion. In otherembodiments, the pedicle may be prepared with other instruments known inthe art, including but not limited to an awl, a trocar, and a needle.

Once the pedicle is prepared, a cannulated anchor, such as screw 32attached to sleeve 50 or 170, may be paced over the guidewire andadvanced through the working cannula to the prepared hole. A drivingtool such as a cannulated screw driver may be used to rotate screw 32and threadedly engage screw 32 to the bone. Sleeves 50 or 170 followsscrew 32 toward the bone as screw 32 is driven therein and the screwdriver and guidewire may be removed. The working cannula may alsosubsequently be removed, leaving the sleeve 50 or 170 and screw 32secured to the bone.

With the anchors 12, 14 secured to the bone and sleeve 50 or 170extending therefrom, the coupling element 42 of anchors 12, 14 and theslots or openings 76 of each sleeve may be oriented or aligned. In oneembodiment an alignment tool (not shown) may be attached to the proximalends of the sleeves to ensure proper alignment of corresponding slots 76of the sleeves 22, 24 and the channels 26 of the coupling element 42 ofeach anchor 12, 14.

Stabilization member 16 is positioned on insertion device 30 and readiedfor insertion into the channels 26 of anchors 12 and 14, respectively.Insertion device 30 may be inserted into sleeve 22 with thestabilization member 16 initially in a generally vertical position (asshown in FIG. 10). As insertion device 30 is advanced in the distaldirection within sleeve 22 and shaft 142 is moved in the distaldirection, rod 100 rotates or pivots about pivot axis 126 to a morehorizontal position (as shown in FIG. 11). In this regard, insertiondevice 30 moves stabilization member 16 in a distal direction towardanchors 12, 14. The proximal end of rod 100 swings outward throughopening 76 of sleeve 22 and the distal tip 108 of stabilization member16 is advanced toward the aligned channels 26 of anchors 12, 14. In onepreferred embodiment, as the insertion device 30 is advanced distallyinto sleeve 22 and shaft 142 is advanced distally with respect to theouter body 140 of insertion device 30, the tip 108 of stabilizationmember 16 follows a generally elliptical path entering the patientthrough first opening 18 and traveling toward the second anchor 14 andthrough the channel 26 of the second anchor. With rod 100 in a morehorizontal position, rod 100 may be then inserted into the channel 26 ofthe first anchor 12 by advancing the rod insertion tool 30 distallytoward the distal end of sleeve 22.

Once stabilization member 16 is placed within channels 26 of anchors 12,14 to the desired position, a cap and/or set screw may be drivendownward through sleeve 24 to contact stabilization member 16 and fixstabilization member 16 to anchor 14. A driving tool may be placedthrough the central channel of sleeve 24 to tighten the cap and/or setscrew against the stabilization member until the stabilization member isfirmly seated in coupling element 42 of anchor 14. With thestabilization member 16 fixed to anchor 14, insertion device 30 can thenbe uncoupled from stabilization member 16 and removed from sleeve 22 anda cap may be inserted through sleeve 22 in a similar fashion to fixstabilization member 16 to anchor 12. For sleeve 50, the outer sleevemember 54 may be retracted such that inner sleeve member 52 is in anextended condition (as shown in FIG. 3) such that arms 72, 74 of theinner sleeve member may be expanded outward to be removed around theinstalled stabilization member 16. In an alternate embodiment, whensleeve 170 is used, the distal end 176 is broken along break line or cut196 to allow the distal end 176 of sleeve 170 to be removed around theinstalled stabilization member 16.

While the invention herein disclosed has been described with referenceto specific embodiments and applications thereof, numerous modificationsand variations can be made thereto by those skilled in the art withoutdeparting from the scope of the invention as set forth in the claims.

What is claimed is:
 1. A method for inserting a vertebral stabilization member percutaneously, comprising: providing a stabilization member extending from a proximal end to a distal end along a first longitudinal axis; providing a stabilization member insertion device releasably linked to the stabilization member; providing a first sleeve and a second sleeve attachable to a first bone anchor and a second bone anchor, attaching the stabilization member to the stabilization member insertion device; inserting the stabilization member insertion device percutaneously into a patient; and using the stabilization member insertion device positioning the stabilization member between the first and second bone anchor, wherein the insertion device extends from a proximal end to a distal end along a second longitudinal axis, the insertion device comprising a first member and a second member, wherein the first member is linearly translatable with respect to the second member along the second longitudinal axis, wherein the stabilization member is linkingly engaged to the first member at a first axial location along the stabilization member and rotatably engaged to the second member at a second axial location along the stabilization member that is axially offset from the first axial location such that, when the first member is translated with respect to the second member along the second longitudinal axis the stabilization member rotates about the second member; and wherein the stabilization member is actuatable by the insertion device from a first orientation substantially parallel to the second longitudinal axis to a second orientation substantially perpendicular to the second longitudinal axis wherein at least one of the first and second sleeves includes one or more resilient tabs integral with a sidewall of at least one of the first and second sleeves, wherein one or more of the resilient tabs includes a ramp portion and lip portion.
 2. The method of claim 1, wherein the stabilization member comprises a rod extending from a proximal end to a distal end along a rod axis.
 3. The method of claim 2, wherein the rod has a curvilinear shape.
 4. The method of claim 2, wherein the rod has at least one indentation along its length, wherein the stabilization member insertion device is rotatably linked to the stabilization member about the indentation.
 5. The method of claim 4, wherein the rod has a pair of indentations coaxially aligned on an axis that extends generally perpendicular to the first longitudinal axis and generally defines an axis about which the rod may pivot.
 6. The method of claim 5, wherein the indentations comprise semispherical concave shapes that cooperatively engage semispherical protrusions of the first member of the insertion device.
 7. The method of claim 6, wherein the first member comprises forked arm portions that may be resiliently expanded to allow the protrusions to snap into the indentations.
 8. The method of claim 5, wherein indentations are semi-circular.
 9. The method of claim 5, wherein indentations are rectangular.
 10. The method of claim 5, wherein indentations are triangular.
 11. The method of claim 1, wherein the stabilization member insertion device is operable to place the stabilization member through a small opening in the skin of a patient in a first orientation.
 12. A method for inserting a vertebral stabilization member percutaneously, comprising: providing a stabilization member extending from a proximal end to a distal end along a first longitudinal axis; and providing a stabilization member insertion device releasably linked to the stabilization member, providing a first sleeve and a second sleeve attachable to a first bone anchor and a second bone anchor, wherein the insertion device extends from a proximal end to a distal end along a second longitudinal axis, the insertion device comprising a first member and a second member, wherein the first member is linearly translatable with respect to the second member along the second longitudinal axis, wherein the stabilization member is linkingly engaged to the first member at a first axial location along the stabilization member and rotatably engaged to the second member at a second axial location along the stabilization member that is axially offset from the first axial location such that, when the first member is translated with respect to the second member along the second longitudinal axis the stabilization member rotates about the second member, wherein the rod has at least one indentation along its length, wherein the stabilization member insertion device is rotatably linked to the stabilization member about the indentation; and wherein the stabilization member is actuatable by the insertion device from a first orientation substantially parallel to the second longitudinal axis to a second orientation substantially perpendicular to the second longitudinal axis wherein at least one of the first and second sleeves includes one or more resilient tabs integral with a sidewall of at least one of the first and second sleeves, wherein one or more of the resilient tabs includes a ramp portion and lip portion.
 13. The method of claim 12, wherein the indentation has a spherical shape and wherein the second member has a prong configured and dimensioned to engage the indentation.
 14. The method of claim 12, wherein the rod has a forked end, and wherein the stabilization member insertion device is rotatably linked to the stabilization member about the forked end.
 15. A method of percutaneously installing a vertebral stabilization system comprising the steps of: creating a first and second opening in a body of a patient; positioning a first anchor to a vertebral body through the first opening with a first access sleeve connected to the first anchor; positioning a second anchor to a vertebral body through the second opening with a second access sleeve connected to the second anchor; positioning a stabilization member through the first opening to engage the first anchor, positioning the stabilization member along the longitudinal axis through the central channel in the first access sleeve in a first orientation substantially parallel to the longitudinal axis of the first access sleeve; and rotating the stabilization member with respect to the insertion device independent of movement along the longitudinal axis such that the stabilization member extends in a second orientation angled with respect to the first orientation to position the stabilization member in relation to the first anchor, positioning the stabilization member such that the stabilization member is positioned within the first and second anchor; wherein the stabilization member is rotatably linked to the insertion device, and the insertion device is configured and dimensioned to be received within the first access sleeve such that the insertion device and stabilization member are moveable in the longitudinal direction to position the stabilization member adjacent the first anchor wherein at least one of the first and second access sleeves includes one or more resilient tabs integral with a sidewall of at least one of the first and second sleeves, wherein one or more of the resilient tabs includes a ramp portion and lip portion.
 16. The method of claim 15, wherein the stabilization member is locked within the first and second anchors with a first and second locking cap.
 17. The method of claim 15, further comprising the step of removing the first and second access sleeves. 